The broad and long-term objectives of the Center are to elucidate the endocrine and neuroendocrine control systems which govern the reproductive processes in a representative primate, the rhesus monkey. The Center comprises the following project and research resources (cores): The Properties of the Pituitary Glycoprotein Hormones; The Neuroendocrine Control of Reproduction in the Male Rhesus Monkey; Cellular Basis of Control of Gonadotropin Hormone Section by Gonadal Steroids; Control of Folliculogenesis in the Rhesus Monkey; Gonadal Hormone Metabolism in the Rhesus Monkey. The cores are: The Primate Research Laboratory (Primate Core), A Steroid Hormone Radioimmunoassay Laboratory, A Polypeptide Hormone Radioimmunoassay Laboratory, and an Administrative Core. The Primate Core houses 280 rhesus monkeys and provides all attendant facilities for their acquisition and care. The Center is also the focus of a major postdoctoral training program in primate reproduction.